As disclosed in Korean Patent Registration Publication No. 10-0548310 (Jan. 24, 2006), the conventional washing machine includes: an outer case forming an outer shape; an outer tub which is supported on an inside of the outer case and receives wash water therein; an inner tub which is rotatably accommodated in an inside of the outer tub and is used for both washing and dehydrating; a pulsator which is mounted in an inside of the inner tub relatively rotatably, to form a washing water flow; a drive motor for generating a driving force for rotating the inner tub and the pulsator; an inner tub rotating shaft which receives the driving force of the drive motor for rotating the inner tub; a pulsator rotating shaft which receives the driving force of the drive motor for rotating the pulsator; a sun gear which is connected to the drive motor and is connected to the pulsator rotating shaft; a plurality of planetary gears which are simultaneously engaged with both the sun gear and a ring gear; a carrier supporting the planetary gears so as to be rotated and revolved; and a clutch spring for controlling the rotation of the inner tub and the pulsator during washing or dehydrating.
The conventional washing machine has a planetary gear set including the sun gear, the ring gear, the planetary gears and the carrier, and reduces the rotational force of the drive motor, to then be transferred to the pulsator and the inner tub, and operates the clutch spring to selectively transmit power to the pulsator and the inner tub, to thus rotate only the pulsator or both the pulsator and the inner tub in an identical direction simultaneously.
However, the conventional washing machine needs the planetary gear unit and the clutch spring in order to selectively rotate the pulsator and the inner tub, to accordingly cause the configuration of the conventional washing machine to be complicated and the production cost thereof to increase.
Further, since the conventional washing machine is configured to have the planetary gear set and the clutch spring between the drive motor and the outer tub, the space occupied in the height direction of the washing machine is increased and thus the height of the washing machine increases. Otherwise, since the height of the inner tub should be reduced in an identical height of the washing machine, there is a problem that a washing capacity is reduced.
Furthermore, when the pulsator rotating shaft is rotated in only one direction where the clutch spring is compressed upon dehydration of the conventional washing machine, the clutch spring is tightened to the outer peripheral surfaces of a first clutch drum and a second clutch drum, whereby the pulsator rotating shaft and the inner tub rotating shaft are integrally rotated in an identical direction at an identical speed by the tension of the clutch spring. In this case, conventionally, a bearing rotatable only in one direction is used as a bearing for supporting the planetary gear set.
As a result, since the conventional washing machine has a structure that the pulsator and the inner tub can be rotated only in an identical direction, but cannot be rotated in opposite directions to each other, there is a problem that a variety of wash water flows cannot be formed and there is a limit to improve performance of the washing machine.